Abnormal Thyroid. (T4)

[Jennifer and Jack]

Jack has his normal annual exam this past Friday which included the senior panel. Thankfully, his liver and kidney numbers are perfect.  Once again, his T4 came up low Less than 0.5.  This is an ongoing theme with him.  Every year, I pursue the further "more sensitive" testing which includes the TSH and T3. Every year, It is normal.

This year I decided, with the vet's encouragement, not to pursue the extensive testing.  I put an email in to his cardiac team at the University of Fla as they monitor all his health concerns in preparation for surgery or possible surgery.  From my limited understanding, T4 can have false lows due to an inflammatory process or some other disease but I don't have any idea what that could be-his blood work doesn't give any indications.

The only sign of possible hypothyroid is lethargy but that can be linked to his other medical conditions. Does anyone have experience with "false lows" with their dog and if so, how did you resolve it?

[Nancy, Ned, Clancy, and Charlie]

I had a dog who did have a low thyroid - symptoms for him were grumpiness and he lost his topcoat. Once he was on thyroid meds, both symptoms disappeared.